Belt gearing



uy 1129 @3g L. K. RAREN BELT GERING Filed Dec., 4. 192s 3 Sheets-Sheet l Lorenz Kon Fad Braven INVENTQR;

By kJ 'alla Attorney.

.Fuy l2, i932. L. K. B RAREN y L867490 BELT GEARI-NG med Dec. 4, 1923 sheets-sheet 2 Loren-z Konrad Brave.

INVENTOR;

By md() Attorney,

my m i932 L. K. BRAREN l@ BELT GEARING FiledvDec. 4, 1923 HIIIIII Loremz Konrad Buuren INVENTQR;

L A Harney.

Patented July l2, 1932 lUNITED s'rArss-I LORENZ KGNRAD OFIUNICH, GERMANY, ASSIGNOB TG THE FIRM FRIEDRICH DECKEL, .FABRIK BAV r L i Application filed December 4, 1933, Serial No.

ithout any variation in the total length of the driving means, of course, there cannot beexerted belt pull on the driven spindle. The

driven shaft may be movable in one, two. or all three directions. The an lar relation of the driven to the driving s aft mayu also be varied to suit the requirements ofthe particular application. f

A further object of the invention is to prof videv means for taking up slack in case of stretch occurring in the driving means, thus rmitting the use of belts that have been' abricated in endless form without variation in thiclmess.

Fig. 1 is a side view of the belt gearing applied for illustrative purposes to an engravf in machine. 'e

ig. 2 is an end view according looking from the right. e Fig. 3 is a top view showing the gearing dia ammatically in two different positions.. ig. 4shows in detail the connection of the 8 drive to the driven spindle.

' Fig. 5 is identical to the lower portion'of Fig. 2 but shows the arrangement when driven by a motor.

5 Fig. 6 shows the applicationof the belt gear in slightly different form toa spindle performing only axial movements.

Figs. 7, 8 and 9 show the application of the belt gear for driving a spindle that may be adjusted to various angular positions.

A stationary shaft 1 is turnably mounted on ball bearings 4 in a suitable bracket 2, which may be either an integralpart of the machine frame 3 or a separate piece. A

bushing 5 is held by a screw cap 6 and one of the ball bearings 4 concentric to the stationary shaft 1 but with suicient space left between the two for lubricant to enter. A pulle 7 is fastened to one end of the shaft 1 an a driving pulley 8 to the other end.

to Fig. 1

FR PRZISIONSHECHANIX'UND IASCHINEEIBAU, OF Hlll'll'llt'JH,v

BELT GEARING 678,486, and in Germany December 11, 1922.

The pulley 7 is driven by a beltfrom a motor or countershat, which drive has not been shown. An arm 9 is turnably mounted on the bushing 5, a grease cup 50 being rovided for lubricating these bearing sur aces and the ball bearingsv 4 through holes provided inthe bushing 5. One end of the arm 9 is formed as a counterweight 33 and on the other end there are `two projecting lugs 10 and 11 in which two pintle screws 12 and 13 are located. These pintle screws are adjustableto allow a bracket 14 to turn fregi' yet without play. A shaft 15 is fasten in the head or bracket14 providing on a substantially vertical axis on each side of the bracketa bearing for two idler pulleys 16 and 17 respectively, a screw 18 on the one end and a' shoulder of the shaft 15 on the other end of thel shaft preventing axial movement. A grease Icup 19 screwed over the shoulder of the shaft presses lubricant through a hole in the center of the shaft 15 to the bearing surfaces. An arm of the bracket 14 protrudes upwards carrying a pin 20 on which a holder 21 may rock.- The center line of pin 20 and the axis formed by the holes for the pintle screws 12 and 13 are located at such distances from the shaft 15 that the belt 22 passing from the driving pulley, 8 over the idler pulleys 16 and 17 to the driven pulley 23 runs on or oil the idler pulleys substantially in the planes of these lines. In other words, the axis of the pintle screws 12 and 13 is substantially tangent to the cylindrical surface defined by the peripheries of the guide pulleys 16 and 17, while the axis of the pivot pin 20 lies substantially in or is an element of such cylindrical surface. A connecting rod 24 is held adjustably. in the rocking holder 21 by a screw 25. In this way the drive may be readily tensioned for varying lengths of the driving means, facilitating thus the use of endless friction belt transmission. A

The pulley 23 isfastened to a driven shaft 26. In Figure 1 the belt gear is shown applied to an engraving machine, where the driven shaft 26 or cutting Atool s indle is mounted in a housing or cutter head 27, free lo 'to move axially. A link 28 is turnably lcon- 'nected on one end toa bracket 51 of the tion to the frame 3 and on the other end to the housin 27, thus allowing the end of the housing 2 which forms the bearing for the shaft 26 of the bushin '30. The faces of the bushing and o the fork 29 in Contact with each other are ball shaped with a radius swung from the center of the shaft 26, where it pierces the plane of the belt groove of the pulley 23. The connecting rod rests loosely `in a corresponding hole of the fork 29. In

this way it is possible for the shaft 26 to assume any osition, also angular lin relaxed shaft 1 without changing the length of the driving means 22 as may readily be understood from the above def scripltion and the drawings Figs. 1 and 3.

T e use of an electric motor simplifies the arrangement of the drive, as is shown in Fig. 5. In this case the driving pulley 8 is lmounted on the motor shaft coaxially with the bushing 5, which is held inplace by a slightly di erent screw cap 34.

In the type of engraving machine described in Figures 1 to 5, the invention thus rovides an endless friction belt transmission or driving the cutter spindle pulley, with supporting means for said transmission constructed and arran ed to maintain said transmission under uni orm tension embodying the counter-balanced upright vertically swingable lever 9 having a lateral push and pull con` nection 24 between the laterally movable cutter head and the horizontal oscillatory lcross head 14,which latter is supported independently of the pantograph mechanism and head 27 in a position spaced from and to one side of the cutter head. The belt transmission may thus be maintained under uniform tension by the universally movable mechanical connection 24 between the cutter head and the counter shaft support 14, the

counter shaft support being oscillated and operating to swing the upright lever 29 as t e cutter head isV movedv over the work.

ln Fig. 6 asimilar belt drive is shown applied to a spindle moving only axially. Here the am's of the driving shaft 35 and the axis 36 on which the arm 37 turns are not arranged coaxially but a distance equal to the radius of the idler pulley 38 apart.

The connecting rod 39 joins the shaft 40 of the idler pulley at a sleeve 43 on the driven shaft 41 which is located below the driven pulley 42 a distance also equal to the radius of the idler 38. Thus two paralleloams are formed that insure always a constant belt length as may be seen by the dotted lines indicating a different position.

In the Figures 7, 8 and 9 the application of the belt gear is shown to a spindle assuming various angular positions. The drive itself is identical to the one shown in Fig. 1. The driven shaft 44 is journaled in two bearings 45 and 46 which form part of a bracket 47. The latter is turnably located on a pivot stud 48, so that the driving pulley 49 assumes different positions as may be seen most readily in Fig. 9.

Having now fully explained my invention I do not wish to be understood as limiting myself to the exact details of construction nor to the particular applications shown, as obviously many modifications will occur to a person skilled in the art.

What I claim is:

' 1. In an engraving machine and the like, in combination, a cutter head provided with a rotary cutting tool spindle having a driven ulley for driving said spindle, mechanism or moving said head laterally over the work, an endless friction belt transmission for driv ing said pulley, and supporting means for said transmission constructed and arranged to maintain said transmission under uniform tension', said supporting means embodying a counter balance upright vertically swingable lever having lateral push and ull connection with said cutter head inc udin a head carried by said lever and rotata le on a vertical axis and carrying pulleys for mately uniform driving tension with respect to said spindle what-ever the operative lateral position of the head over the work, said means embodying a fulcrumed counterbalanced member carryingtransmission belt ulleys, said member being supported inependently of said head and being con. nected therewith to constantly'maintain the relative ositions of the head and member durin t e lateral movements of the head overt ework. y

3. An engraving machine andthe like,- comprisingy a cutter head carrying a rotary cutter spindle, means to move the head laterally over the work, a belt transmissionfor driving said spindle, and means for mainmovements-of the head over the work, said .means embodying a vertically swingable eratively connected with said cutter head to constantly maintain relative positions of the cutter head and cross head during the operative lateral movements of the cutter head over the work.

4. In an engraving machine and the like, a cutter head movable in various directions laterally over the work and provided with a rotary spindle adapted to receive a cutter to operate on the work, said spindle having a driving pulley, in combination with an endless friction belt, transmission drive for said pulley, pulleys for said drive and supports for said pu leys embodying a pivotally mounted elongated arm at itsfree end spaced laterali from and swingable toward and from sai nected therewith b spindle driving beit means other than the to maintain approxivmately uniform tension of said belt on said spind pulley during the lateral movements of the head over the work.

5. An engraving machine, comprising a cutter head having a rotary cutter spindle and its driving pulley, means for shifting said head horizontally over the work, and a driving transmission for said pulley embodying a main drive pulley, an endless friction belt drive from said drive pulley to said 'spindle driving pulley and supporting and guide means'forsaid friction belt drive comprising an upright lever vertically swingable from a transverse supporting axis at its lower end, a support carried by the free end of said lever and relatively oscillatory on a vertical axis and provided with belt pulleys and a mechanical connection between said cutter head and said counter shaft support to oscillate said supportand swing said lever as the cutter head is moved over the work to maintain said drive belt under uniform tension.

6. In a machine drive, a horizontal driving shaft provided with a. pulley, an arm pivoted on said driving shaft to swing in a vertical plane, means for counterbalancing said arm, a member pivoted on said arm about an axis lying` substantially in a plane .containing said driving shaft, pulleys on said member, a driven shaft provided with a pulley, a bearing supporting said dri-ven shaft in substantially vertical position for movement horizontally over the work a second arm connecting said member and bearing to maintain a constant distance' therebetween, and belt means passing over said pulleys on said member and shafts.

7 In a machine drive, a. horizontal drivin shaft provided with a pulley, an arm pivoted on said driving shaft to swing in a verticalplane, means for counterbalancing said arm,

head and operatively 'conshaft, ulle s on said member, a. driven shaft provi ed with a pulley, a bearing supporting said driven shaft in substantially vertical position for movement horizontally over the work, asecond arm pivoted'on said member about a substantially horizontal axis and connected with said bearing, said second arm having means for adjusting the length thereof and operating to maintain a constant spacing betweenV said member and bearing, Vand belt means passing over said pulleys on said member and shafts.

8. In a machine drive, a driving shaft provided with a pulley, an arm pivoted on said driving shaft to swing in a substantially vertical plane, means for counterbalancing said arm, a member provided with guide pulleys and pivoted on said arm about an axis extending longitudinally of said arm and substantially tangent to .the cylindrical surface defined by the peripheries of said guide pulleys, a driven shaft provided with a pulley, a bearing supporting said driven shaft in substantially vertical position for movement horizontally over the work, a second arm pivoted on said member about an axis lying substantially in said cylindrical surface and connected with said bearing to maintain a predetermined spacing between said member and bearing, and belt means passing over' the pulleys on said member and shafts.

9. in a machine drive, a driving shaft provided with a pulley, an arm pivoted on said ldriving shaft to swing in a substantially vertical plane, means for counterbalancing said arm, a member provided with guide pulleys and pivoted on said arm about an axis extending longitudinally thereof, a driven shaft provided with a pulley, a bearing supportingber and provided at its other end with a fork embracing said bearing, said arm having means for adjusting the length thereof and operating to maintain a constant spacing between said member and bearing, and belt means passing over said pulleys of said member and shafts.

1 0. In a machine drive, a driving shaft provided with a pulley, an arm ivoted on said driving shaft to swing in a su stantially vertical plane, Ameans for counterbalancin ysaid arm, a member provided with guide. pu leys and ivoted onsaid arm about an axis extending ongitudinally ofsaid arm and substantially tangent to the cylindrical surface f defined by the leys, a driven s aft provided with a pulley, a. bearin supportin said driven shaft in substantia y vertica position for movement iliorizrc'mtally over the work, a second arm pivlying substantially in said cylindrical surface and provided at its other endwith a fork ripheries of said guide pul- 'oted' at 'one end on said member about an axis i loosely embracing said bearing, saidY arm having means for adjusting the length thereof to maintain a predetermined spacing between said member and bearin and belt means passing over said pulleys o said member and sha 11. In a machine drive, a driving shaft provided with a driving pulley, an arm pivoted on said shaft, a member provided with a. guide pulley and pivoted on said arm about an axis substantially tangent to the cylindrical surface formed by the projection of the peripheryV of said guide pulley, a driven shaft provided With a driven pulley, a bearing for said driven shaft `for moving the same laterally parallel with itself over the Work, a second arm connected'at one end With said driven shaft and at the other end pivoted to said member about an axis substantially lying in said cylindrical surface, and belt means passin over said driving and driven pulleys and sald guide pulle 12. In a maciine drive, a driving shaft provided with a driving pulley, a pivot/ed arm, a member providedwith guide pulleys, said member being mounted on said pivoted arm to swing about an axis substantially tangential to the peripheries of said pulleys and said pivoted arm being mounted to swin about an axis s aced from the axis of sai driving shaft a istance substantially equal to the radius of said guide pulleys, a driven shaft provided with a driven pulley, a bearingtsupporting said driven shaft for move.-

ment laterally 1n diiierent directions over the work, a, second arm pivoted on said member substantially about the axis of saidguide pulleys and connected at its other end with said driven shaft at a distance from said driven pulley substantially equal to the. radius of said guide pulleys for maintaining'a predetermined s acin between said member and driven sha ,an belt means passingover said driving and driven pulleys and said guide pulleys. 1 Y

In testimony Whereofl hereunto aix my signature. l

LORENZ KONRAD BRAREN. 

